JP5677875B2 - Non-contact power transmission system - Google Patents

Description

  The present invention relates to a non-contact data communication means, a non-contact power transmission means utilizing magnetic resonance, a device, and an antenna for transmitting and receiving them, and by non-contact to a portable device equipped with a non-contact IC card or a battery. The present invention relates to a technology that is effective when applied to a charging device.

  As a technique studied by the present inventor, for example, a conventional structure of a non-contact charging system may be configured as shown in FIG.

  FIG. 24 is a block diagram showing an example of the prior art of a non-contact charging system. The system shown in FIG. 24 has a power transmission device 701 provided on a power provider side such as a railway station or a store, and a user. And a portable terminal device 702. In this system, the mobile terminal device 702 is charged by the power transmission device 701.

  The power transmission device 701 includes a non-contact processing module 713 such as an RFID reader, a non-contact power transmission module 712, and a power transmission control module 711.

  The mobile terminal device 702 includes a non-contact processing module 723 for non-contact processing operation such as RFID, a non-contact power receiving module 722 for charging, a power receiving control module 721 for determining and controlling charging, And a large-capacity power storage module 720 that can be charged at high speed.

  In the figure, a user who owns a mobile terminal 702 is connected to a non-contact type processing module 713 installed in a power transmission device 701 installed in a station or a store, and a non-contact type processing installed in the mobile terminal 702. When data transmission is performed between the modules 723 to perform electronic payment or the like, the non-contact power transmission module 722 mounted on the power transmission apparatus 701 is contacted with the non-contact power transmission module 722 on the terminal side in a non-contact manner. The non-contact power transmission module 722 rectifies the received power and charges the high-speed large-capacity power storage module 720. The power transmission control module 711 and the power reception control module 721 shown in FIG. And non-contact power transmission control at the same time, and charge the high-speed large-capacity power storage module 720 It is performed to control the power.

  In the above configuration, since the power of the mobile terminal device 702 is charged while communication is performed between the non-contact processing modules 713 and 723, the charging time of the mobile terminal device 702 can be reduced. If communication is frequently performed between the non-contact processing modules 713 and 723, the terminal can be continuously used without particularly charging the portable terminal device 702 (see, for example, Patent Document 1).

  Furthermore, in the non-contact communication and the power transmission for charging shown in FIG. 24, the non-contact communication and the non-contact power transmission at a relatively short distance of several centimeters or less have a magnetic coupling such as an electromagnetic induction method and a magnetic resonance method. Transmission by is common. This is because the transmission method using radio waves, which is considered to be dominant as another transmission method, is inversely proportional to the transmission distance r, while the strength of transmission by electromagnetic coupling is inversely proportional to the square of the transmission distance r. This is because the term 1 / (r2) becomes larger than 1 / r when 1 becomes smaller than 1 m.

  For this reason, the frequency used for power transmission for non-contact communication or charging is a frequency of about 100 MHz from the 100 kHz band, and as an antenna used for these transmission and reception, in order to strengthen the magnetic coupling, As shown in FIG. 25, it is common to use a coil-shaped antenna of several to several tens of turns, and the diameter is 4 cm as in the non-contact communication and non-contact power transmission used in the portable terminal shown in FIG. A coil-shaped antenna of a degree is used (for example, see Non-Patent Document 1).

  As other techniques studied by the present inventors, those described in Non-Patent Document 2 and Patent Document 2 are known. As for this non-contact power transmission system, for example, a configuration as shown in FIG. 26 can be considered.

  FIG. 26 is a block diagram showing an example of a conventional technology of a non-contact power transmission system. The non-contact power transmission system 730 is a high-frequency power source 731 and a feeding coil 732 connected to the high-frequency power source 731 via a variable impedance circuit 737. The resonance coil 733 constitutes a primary coil, the resonance coil 734 and the load coil 735 constitute a secondary coil, and a load 736 connected to the load coil 735 is provided.

  Further, resonance capacitors 738 and 739 are connected to the resonance coils 733 and 734, respectively. The power supply coil 732, the resonance coils 733 and 734, and the load coil 735 constitute a resonance system 740. The output frequency of the high frequency power source 731 is set to the resonance frequency of the resonance system 740.

  The impedance variable circuit 737 includes two variable capacitors 741 and 742 and an inductor 743. One variable capacitor 741 is connected in parallel to the high-frequency power source 731, and the other capacitor 742 is connected in parallel to the feeding coil 732. The inductor 743 is connected between the variable capacitors 741 and 742. The impedance variable circuit 737 changes its impedance by converting the capacitances of the variable capacitors 741 and 742. The impedance variable circuit 737 is adjusted in impedance so that the input impedance at the resonance frequency of the resonance system 740 matches the impedance on the high-frequency power source 731 side. The variable capacitors 741 and 742 have a known configuration in which the capacity is varied by driving the rotation shaft by a motor, and the motor is driven by a drive signal from the control device 744.

  A high frequency voltage is output from the high frequency power source 731 to the feeding coil 732 via the impedance variable circuit 737 at the frequency of the resonance system 740, and a magnetic field is generated in the feeding coil 732. This magnetic field is enhanced by magnetic field resonance by the resonance coils 733 and 734. Electric power is extracted from the magnetic field near the enhanced resonance coil 734 by the load coil 735 using electromagnetic induction and supplied to the load 736.

  At this time, when the inter-coil distance of the resonance coils 733 and 734 changes, the input impedance of the resonance system 740 also changes. For this reason, when there is no impedance variable circuit 737, impedance matching cannot be achieved depending on the distance between the coils of the resonance coils 733 and 734, and reflected power to the high-frequency power source 731 occurs, resulting in a decrease in transmission efficiency. From another viewpoint, since the frequency at which the magnetic resonance phenomenon occurs varies depending on the distance between the coils, transmission loss increases when the magnetic resonance frequency deviates from the output frequency of the high frequency power supply 731. For this reason, the frequency of the high-frequency power source may be adjusted to the frequency with the smallest transmission loss in accordance with the distance between the coils, but it is not general because changing the transmission frequency may affect other communication devices. . For this reason, when the distance between coils fluctuates and the input impedance of the resonance system 740 fluctuates, the control device 744 adjusts the variable capacitors 741 and 742 to achieve impedance matching.

Japanese Patent Laid-Open No. 2006-353042 FIG. Japanese Patent Laid-Open No. 2010-141976 FIG.

Nikkei Business, January 26, 2009 issue, 78 pages, Nikkei Business Publications, Inc. NIKKEI ELECTRONICS 2007.12.3 117-128

  By the way, in the charging system of the prior art shown in FIG. 24, since non-contact communication and non-contact power transmission are used individually, a coiled antenna having a diameter of about 4 cm is required. For this reason, when it is intended to mount the charging system as shown in FIG. 24 on a portable terminal that is particularly demanded for miniaturization, it is necessary to incorporate the above-described coiled antenna, so that the portable terminal device is small. It had the problem that it was difficult to make it.

  Further, in the conventional charging system shown in FIG. 24, in non-contact power transmission, if the transmission loss of the non-contact portion is large, the efficiency of the power transmission device is reduced and the power consumption is increased. However, when the transmission distance is increased to some extent (for example, about 1 to 2 cm), the transmission efficiency is rapidly deteriorated. When the power receiving device is to be mounted, it is necessary to shorten the transmission distance between the power transmitting device and the power receiving device during charging by, for example, attaching the antenna of the power receiving device to the surface of the mobile terminal device. Therefore, there is a problem that the mounting position is limited.

  Furthermore, the communication frequency of the portable terminal device is a relatively high frequency in the 800 MHz band and the 2 GHz band, and the antenna used for this communication has been miniaturized and can be built in the communication terminal. However, when an antenna for receiving the above-mentioned contactless communication or power transmission by contactless is built in the mobile terminal, the radio wave from the communication antenna of the built-in mobile terminal device is from the frequency at which the power is transmitted by contactless communication or contactless power transmission. However, the antenna that receives power by non-contact communication or non-contact looks only like a metal plate. For this reason, since reflection occurs in the antenna unit that performs non-contact communication or non-contact power reception, the reception sensitivity of the mobile terminal device is affected.

  In the non-contact power transmission system of the prior art shown in FIG. 26, the resonance system input impedance fluctuates due to the fluctuation of the inter-coil distance of the magnetic resonance coil, so that the primary coil side and the secondary coil side are changed. The phenomenon of transmission efficiency degradation due to the change in the frequency characteristics of the power supply is improved by adjusting the variable capacitance of the variable impedance circuit to achieve impedance matching between the high frequency power supply and the resonance system. In this case, it is difficult to use a semiconductor such as a variable capacitance diode for the variable capacitance due to problems of power capacity and breakdown voltage. For this reason, since it is necessary to use a mechanical variable capacitor such as a variable capacitor, the size of the power transmitter cannot be reduced. Moreover, since the variable capacity is mechanical, there is a problem in terms of durability.

  Furthermore, in the non-contact power transmission system shown in FIG. 26 described above, in the transmission at a very short distance of about several millimeters between the magnetic resonance coils, electromagnetic induction is different from transmission by magnetic field resonance between the magnetic resonance coils. As a result, an increase in the rate of transmission caused by the transmission caused an effect that transmission efficiency would be lowered if the coil was made closer.

  In order to achieve the above object, the present invention has a problem that it is difficult to reduce the size of a portable terminal device when an antenna for receiving non-contact communication and non-contact power transmission, which is the above problem, is mounted. If the shared antenna receives the transmitted power from the power transmission device by sharing the antenna that receives power without contact with the antenna and providing a switching circuit in the reception output section of the shared antenna, the switching circuit Switching to the charging side, the power reception signal is rectified in the rectifier circuit via this switching circuit and the battery is charged, and when the non-contact communication signal is received, the switching circuit holds the non-contact communication side as it is, Non-contact communication is possible.

  Next, when charging, it is necessary to shorten the transmission distance between the power transmission device and the power reception device so that the efficiency does not deteriorate, so the problem that the mounting position is limited is used for power transmission in the power transmission device. A magnetic resonance system comprising a resonance coil having a coil length that resonates at a frequency used for power transmission as an antenna, and a feeding coil that magnetically couples transmission power to the resonance coil to feed power In this configuration, the transmission power from the power transmission device is supplied from the power supply coil, and the non-contact communication signal is also transmitted superimposed on the power transmission signal.

  Similarly, in the power receiving device, as the antenna used for power reception, the power received by the resonance coil and the resonance coil having both ends of the coil having the same length as the power transmission side resonating with the frequency used for power transmission and the resonance coil are used. A magnetic resonance method was adopted in which received power was extracted from a magnetically coupled load coil.

  With the above configuration, the resonance frequency of the resonance coil on the power transmission side and the resonance coil on the reception side are equal, so that the magnetic flux caused by the current flowing through the resonance coil on the power transmission side and the phase of the magnetic flux caused by the current flowing through the resonance coil on the reception side. Are in phase, the resonance coils are strongly coupled. This phenomenon is called a magnetic resonance phenomenon, and has the feature that there is less decrease in efficiency even when the distance between the coils is longer than the electromagnetic induction method mainly used for conventional non-contact transmission. Even when the distance between the device and the power receiving device is slightly separated, the transmission efficiency is hardly lowered. Therefore, when the power receiving device is mounted on the portable terminal device, the configuration of the mounting position of the power receiving antenna can be reduced.

  Since reflection occurs in the antenna unit that performs non-contact communication and power reception by non-contact, the problem of affecting the reception sensitivity of the mobile terminal device is similar to the problem that the mounting position is limited as described above. A magnetic resonance method is used for the power receiving antenna, and the resonance coil of the power receiving antenna is deleted.

  In this configuration, the power transmission side is the magnetic resonance system and the power reception side is the electromagnetic induction system, but the transmission distance between the coils is such that a transmission distance substantially equal to that when the reception side is the magnetic resonance system is obtained.

  With the above configuration, the power receiving side antenna is only a load coil, so it is only a looped coil of about 1 to several turns with a diameter of about 3 cm, compared with a conventional coil of several tens of turns densely wound. Since the reflection of the radio wave used for communication of the mobile terminal device is reduced, the influence on the communication antenna can be further reduced.

  The means for sharing the antenna when the power transmission frequency and the non-contact communication are the same frequency but different from each other will be described below.

  In general, in the transmission by the magnetic resonance method, the number of turns of the resonance coil is larger and the inductance value is larger than a power supply coil that supplies power to the resonance coil and a load coil that extracts power received from the resonance coil.

  When the frequency of non-contact communication and the frequency of non-contact power transmission are different, the first capacitor is connected in parallel with the receiving-side resonance coil, and the second capacitor is connected in series or in parallel via the first filter circuit. After connecting, the low frequency signal is extracted, and a load coil is provided close to the power receiving coil so as to be magnetically coupled to the resonance coil, and a high frequency is provided to the load coil via the second filter circuit. The first capacitor has a value that resonates with a signal having a higher frequency than the resonance coil, the second capacitor has a value that resonates with a signal having a lower frequency with the resonance coil, and The first filter circuit passes the lower frequency signal and blocks the higher frequency signal, and the second filter circuit passes the higher frequency signal. And configured to prevent the passage of signals towards the lower frequencies.

  With the above configuration, the resonance coil can output a signal having a lower frequency that resonates with the resonance coil and the second capacitor, and the load coil can output with the resonance coil and the first capacitor. The resonating high frequency signal can be output by the magnetic resonance method as in the prior art shown in FIG.

  Here, as an example of the size of the coil used in the non-contact power transmission by the conventional electromagnetic induction method, if it is about 5 W or less used for charging a portable device or the like, it is several tens of centimeters in diameter. The number of turns is about several turns, and in the several kW class used for charging an electric vehicle or the like, the number of turns is about several tens of turns with a diameter of several tens of centimeters. The frequency used is several tens of kHz to several hundreds of kHz, and the transmission distance Is generally several cm or less. In addition, the size of the coil used for non-contact power transmission by the magnetic resonance method is about several tens of turns with a diameter of several centimeters as long as it is about 5 W or less used for charging a portable device or the like. In the several kW class used for charging an electric vehicle or the like, the diameter is several tens of centimeters and the number of turns is from several turns to several tens of turns. The frequency used is from several MHz to several tens of MHz. The number of turns of the power supply coil that supplies power and the load coil that extracts power from the resonance coil is about one turn. In addition, the transmission distance of the magnetic resonance method is about several centimeters to several tens of centimeters, and the distance between the feeding coil and the resonant coil and between the resonant coil and the load coil is generally about 1 cm or less.

  Next, if the variable impedance circuit is used to adjust the fluctuation of the input impedance of the resonance system due to the fluctuation of the inter-coil distance of the magnetic resonance coil (resonance coil), Similar to the problem that the coil becomes larger than the mounted device, the load coil is configured to add a resonance capacitance that resonates with the inductance of the load coil by at least series connection or parallel connection.

  By adopting the above configuration, the fluctuation of the frequency characteristic between the primary coil and the secondary coil due to the fluctuation of the inter-coil distance of the magnetic resonance coil is reduced (the input impedance fluctuation due to the fluctuation of the inter-coil distance is reduced). Since the result has been experimentally obtained, it is possible to suppress the fluctuation of the frequency characteristic between the primary coil and the secondary coil due to the fluctuation of the inter-coil distance without using the variable impedance circuit. The size can also be reduced.

  Furthermore, as means for reducing the fluctuation of the frequency characteristic between the primary coil and the secondary coil due to the fluctuation of the inter-coil distance of the magnetic resonance coil, a plurality of resonance coils on the primary coil side are provided, and each coil is a load coil. By making the number of turns so that the transmission efficiency is the best corresponding to the distance, it is possible to mainly transmit with the most efficient resonance coil corresponding to the distance between the primary side resonance coil and the load coil. Therefore, also by the above means, it is possible to reduce the fluctuation of the frequency characteristic between the primary coil and the secondary coil due to the fluctuation of the inter-coil distance.

  Further, regarding the problem that the transmission efficiency is lowered at a distance as short as several mm between the coils of the magnetic resonance coil, the arrangement of the feeding coil and the coil of the primary magnetic resonance coil is exchanged, and the primary The distance between the feeding coil and the load coil was made closer than the distance between the resonance coil on the side and the load coil. As a result, the transmission efficiency is deteriorated in magnetic resonance transmission in which the primary coil and the secondary coil are about several mm, and a decrease in transmission efficiency can be suppressed even in the case of very short distance transmission. This is because at a very short distance, the power feeding coil and the load coil are close to each other in distance, so that power can be transmitted directly from the power feeding coil to the load coil by electromagnetic induction.

  Further, in the non-contact power transmission system, as a communication means for performing device authentication for confirming whether or not non-contact charging is supported, control of the transmission power amount, and the like, the transmission side transmits ASK (Amplitude) to the signal of the transmission power. (Shift Keying) Modulation such as a modulation method is applied, and a configuration using a load modulation method that enables communication using a received signal without power on the receiving side is relatively simple. A non-contact power transmission system capable of communication can be obtained.

  According to the present invention, even when a non-contact power receiving device for charging a battery with a non-contact communication means is mounted on a portable terminal device or the like, it is possible to suppress the enlargement of the terminal by mounting these as much as possible and When using contact communication or non-contact power reception, contactless power transmission with less transmission loss between antennas and less impact on communication sensitivity of mobile terminal devices, etc., even when the transmission distance is increased by using magnetic resonance. A system, a power receiving device, and a power transmitting device can be obtained.

1 is a configuration diagram illustrating a configuration of a contactless charging system according to Embodiment 1. FIG. It is a block diagram which shows the structure of the non-contact charge system which concerns on Example 2. FIG. It is a block diagram which shows the structure of the non-contact charge system which concerns on Example 3. FIG. It is an experimental result which shows the difference in the transmission efficiency by the distance between coils in a magnetic resonance system and transmission in an electromagnetic induction system and the conventional electromagnetic induction system in transmission. It is an experimental result which shows the difference of the dependence by the distance between coils of the transmission efficiency characteristic in a magnetic resonance system and the conventional electromagnetic induction system. It is an experimental result which shows the difference in the dependence by the distance between coils of transmission magnetic resonance system and reception electromagnetic induction system. 1 is a schematic diagram schematically showing a configuration of a magnetic resonance type coil according to Embodiment 1. FIG. FIG. 3 is a schematic view of the configuration of the magnetic resonance type coil according to the first embodiment when viewed from the side in the transmission direction. It is a block diagram which shows the structure of the non-contact charge system which concerns on Example 4. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 5. FIG. FIG. 10 is a configuration diagram illustrating a configuration of a contactless charging system according to a sixth embodiment. FIG. 10 is a configuration diagram illustrating a configuration of a non-contact charging system according to a seventh embodiment. FIG. 10 is a configuration diagram illustrating a configuration of a contactless charging system according to an eighth embodiment. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 9. FIG. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 10. FIG. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 11. FIG. 10 is a configuration diagram illustrating a configuration of a non-contact charging system according to Example 12; FIG. 18 is a diagram illustrating another example of the primary resonance coil group of the contactless charging system according to the twelfth embodiment. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 13. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 14. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 15. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 16. It is a block diagram which shows the structure of the non-contact charging system which concerns on Example 17. FIG. It is the schematic diagram which showed typically the frequency characteristic of the non-contact charge system which concerns on Example 12. FIG. It is the schematic diagram which showed typically the frequency characteristic of the non-contact charge system which concerns on Example 13. FIG. It is a block diagram which shows the prior art example in the case of performing power transmission by non-contact communication and non-contact. It is the schematic diagram which showed typically the coil structure of the electromagnetic induction system implement | achieved by a prior art It is a block diagram which shows the prior art example in the case of performing non-contact electric power transmission by a magnetic resonance system.

  A first embodiment of a non-contact charging system according to the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a first embodiment having a non-contact charging system used in the present invention.

  In the figure, reference numeral 702 denotes a portable terminal device, 140 denotes a power transmission device that transmits power without contact, 150 denotes a contactless communication device, and the portable terminal device 702 in the figure includes a magnetic resonance coil 101, a load coil 102, and a changeover switch. 110, rectifier diodes 121, 122, 123, 124, 125, 126, 127, 128, smoothing capacitors 130, 131, non-contact data communication unit 103, charge control unit 104, battery 105, terminal wireless communication unit 106, detection The output switch 107 is configured, and attenuation switches 111 and 112 are added to the changeover switch 110. Further, the power transmission device 140 shown in the figure includes a magnetic resonance coil 141, a power feeding coil 142, an amplification unit 143, an oscillator 144, a control unit 145, and a detection unit 146, and the non-contact communication device 150 includes an electromagnetic induction coil 151 and a resonance capacitor 152. , An oscillator 153, and a non-contact data communication unit 154.

  In the figure, a mobile terminal device 702 is provided with a load coil 102 at a distance of about several millimeters from a planar magnetic resonance coil 101 of about 10 or more turns that is not connected at both ends, and an output end of the load coil 102. Is connected to the changeover switch 110. Furthermore, one output of the changeover switch 110 is input to a full-wave rectifier circuit including rectifier diodes 121 to 124, and the rectified output is input to the non-contact data communication unit 103.

  The other output of the changeover switch 110 is input to a full-wave rectifier circuit including rectifier diodes 125 to 128, and the rectified output is supplied to the battery 105 via the charge control unit 104.

  In addition, the power transmission device 140 shown in the figure is provided with a power supply coil 142 at a distance of about several millimeters with respect to a planar magnetic resonance coil 141 of about 10 or more turns that is not connected at both ends, and at the input end of the power supply coil 142. Is connected to an oscillator 144 via an amplifier 143.

  Furthermore, in the non-contact communication apparatus 150 shown in the figure, an oscillator 153 is connected in parallel with a resonance capacitor 152 to the coil end of an electromagnetic induction coil 151 having ten or more turns.

  In the above charging system, first, an operation in the case where communication is performed from the non-contact communication device 150 to the mobile terminal device 702 in a non-contact manner will be described.

  The oscillator 153 in the non-contact communication device 150 oscillates at a carrier frequency at which non-contact communication is performed (for example, 13.56 MHz in the case of RFID), and the non-contact data communication unit 154 oscillates corresponding to data to be transmitted. The frequency is modulated, and the modulated communication signal is efficiently radiated as electromagnetic energy by the antenna adjusted so that the resonance frequency of the electromagnetic induction coil 151 and the resonance capacitor 152 is equal to the carrier frequency.

  On the other hand, in the mobile terminal device 702, since the magnetic resonance coil 101 is adjusted to resonate at a frequency equal to the non-contact communication signal, the most current flows through the coil 101 due to radiation from the non-contact communication device 150. A high voltage is excited at both ends of the load coil 102, and the excited voltage is input as it is to the rectifier circuit including the rectifier diodes 121 to 124 via the changeover switch 110. The input non-contact communication signal is smoothed by the smoothing capacitor 130 to become a DC voltage and supplied to the non-contact data communication unit 103 as a power source, and the modulated data is also demodulated by the non-contact data communication unit 103. On the other hand, the communication from the non-contact data communication unit 103 to the non-contact communication device 150 changes the input impedance of the non-contact data communication unit 103 corresponding to the transmission data with respect to the signal received by the magnetic resonance coil 101. Thus, the non-contact communication device 150 detects that the amount of reflection from the magnetic resonance coil 101 to the electromagnetic induction coil 151 fluctuates, thereby performing communication in the reverse direction.

  Next, an operation when power is transmitted from the power transmission device 140 to the mobile terminal device 702 in a non-contact manner will be described.

  The oscillator 144 in the power transmission device 140 oscillates at 13.56 MHz, which is the same as the RFID used in the non-contact communication device 150, as a frequency for transmitting power in a non-contact manner, amplifies the power in the amplifying unit 143, and feed coil 142 excites the magnetic resonance coil 141. Since the magnetic resonance coil 141 is adjusted so as to resonate at a frequency equal to the power transmission frequency, a strong magnetic field flows with the largest current flowing at the power transmission frequency.

  On the other hand, in the mobile terminal device 702, since the magnetic resonance coil 101 resonates at a frequency equal to the power transmission frequency, the most current flows in the power transmission signal, and a high voltage is excited across the load coil 102. When the excited voltage becomes a certain value or more, the charging control unit 104 switches the changeover switch 110 to the power receiving side, so that the received signal is a rectifying circuit configured by rectifying diodes 125 to 128. Is rectified and converted to a DC voltage by the smoothing capacitor 131 and supplied to the charging control unit 104. The charging control unit 104 charges the battery 105 with the supplied DC voltage, and controls the amount of charge so that the battery 105 is not damaged due to overcharging.

  The detection output unit 107 of the mobile terminal device 702 outputs a specific identifier. When the mobile terminal device 702 approaches the power transmission device 140 and the detection unit 146 detects the identifier from the detection output unit 107, the control unit 145. Starts power transmission with the oscillator 144 turned on.

  Further, when power transmission from the power transmission device 140 is performed, the changeover switch 110 is switched to the power receiving side. At this time, the signal received by the non-contact communication side via the attenuation resistors 111 and 112 is also transmitted to the non-contact communication side. Attenuated and input to the non-contact communication side. With such a configuration, when a non-contact communication signal is superimposed on a power transmission signal, non-contact communication can be performed simultaneously with power reception. Here, the reason why the power reception signal level is lowered by the attenuation resistor is that the level of the power transmission signal is considerably higher than that of the non-contact communication signal.

  With the above configuration, the transmission between the power transmission device 140 and the mobile terminal device 702 is coupled by the magnetic resonance method, so that a charging system with less loss even when the transmission distance is longer than the conventional electromagnetic induction method. Furthermore, by sharing antennas used for non-contact communication and non-contact power transmission, it is possible to suppress the increase in the mounting volume of the portable terminal device 702 due to the mounting of these antennas as much as possible. It becomes possible.

  FIG. 2 is a diagram showing a second embodiment of the non-contact charging system used in the present invention.

  Compared with the first embodiment shown in FIG. 1, the figure uses an electromagnetic induction type coil for the portable terminal device 702 and a magnetic resonance type coil for the power transmission device 220. In addition, although the figure uses the power transmission apparatus 220 in which the communication apparatus and the power transmission apparatus are integrated, the present invention is not limited to this. As shown in FIG. 1, even when the communication device and the power transmission device are separate, an electromagnetic induction type coil may be used for the mobile terminal device and a magnetic resonance type coil may be used for the power transmission device.

  In the figure, 201 is a loop antenna coil of about 2 to 3 turns, 202 and 203 are resonance capacitors that resonate with the loop antenna coil 201 at the transmission signal frequency, and 220 is a non-contact power transmission device that also serves as a non-contact communication means. The power transmission device 220 provided with the non-contact communication means includes a non-contact data communication unit 221. Other parts corresponding to those in FIG.

  When the power transmission device 220 performs non-contact communication with the mobile terminal device 702, the non-contact data communication unit 221 modulates the oscillation signal of the oscillator 144 with communication data, amplifies the modulated signal with the amplification unit 143, and feed coil Transmission is performed by a power transmission antenna composed of 142 and a magnetic resonance coil 141.

  The signal transmitted from the power transmission device is received by the loop antenna coil 201 of the portable terminal device 702 and resonates with the capacitance value of the resonance capacitor 202 via the changeover switch 110, thereby rectifying configured by the rectifying diodes 121 to 124. The highest voltage signal at the transmission frequency is applied to the circuit. The non-contact communication signal output from the rectifier circuit is smoothed by the smoothing capacitor 130 to become a DC voltage, which is supplied as a power source to the non-contact communication unit 103, and the modulated data is also received by the non-contact data communication unit 103. Demodulated.

  Next, an operation when power is transmitted from the power transmission device 220 to the mobile terminal device 702 will be described.

  A power transmission signal is output from the magnetic resonance coil 141 by amplifying the power of the signal of the oscillator 144 in the power transmission device 220 in the amplification unit 143 and exciting the magnetic resonance coil 141 by the power supply coil 142.

  The transmitted signal is received by the loop antenna coil 201 of the mobile terminal device 702. When the received voltage becomes a certain value or more, the charging control unit 104 sets the changeover switch 110 to the power receiving side. Therefore, by resonating with the capacitance value of the resonant capacitor 203 via the changeover switch 110, the rectifier circuit constituted by the rectifier diodes 125 to 128 has the highest voltage at the power transmission frequency, and the received signal is smooth. A DC voltage is supplied to the charging control unit 104 by the capacitor 131. The charging control unit 104 charges the supplied DC voltage to the battery 105 and controls the amount of charge so that the battery 105 is not damaged by overcharging or the like.

  Furthermore, when performing power transmission from the power transmission device 220, the changeover switch 110 is switched to the power receiving side. At this time, the signal received by the non-contact communication side via the attenuation resistors 111 and 112 is also transmitted to the non-contact communication side. Since it is attenuated and input to the non-contact communication side, non-contact communication can be performed simultaneously with power reception by superimposing the non-contact communication signal on the power transmission signal.

  With the above configuration, the same effect as that of the first embodiment can be obtained, and a loop antenna coil of about 2 to 3 turns can be used as a power receiving antenna, so that the portable terminal device 702 can be more It can be made small.

  Furthermore, by using a loop antenna coil of about 2 to 3 turns as a power receiving antenna, reflection of radio waves used for communication of the terminal wireless communication unit 106 is reduced, so that the influence on the terminal wireless communication unit 106 is further reduced. be able to.

  FIG. 3 is a view showing a third embodiment of the non-contact charging system used in the present invention.

  In the figure, 301 is a resonance capacitor, 310 is a changeover switch, 311 is a damping resistor, 312, 313, 314, and 315 are rectifying diodes shared by non-contact communication and non-contact power reception. The parts corresponding to those in FIG.

  In the power transmission device 220, when performing non-contact communication with the mobile terminal device 702, the non-contact data communication unit 221 modulates the oscillation signal of the oscillator 144 with communication data, amplifies the modulated signal with the amplification unit 143, and feed coil Power is transmitted by a power transmission antenna composed of 142 and a magnetic resonance coil 141.

  The transmitted signal is resonated with the transmission frequency signal by the loop antenna coil 201 and the resonant capacitor 301 of the portable terminal device 702 and received with the largest signal amplitude, and is rectified by the shared rectifying diodes 312 to 315. . At this time, if the voltage rectified by the charging control unit 104 is equal to or higher than a certain value, it is determined that the power transmission for charging is performed, and the changeover switch 310 is switched to the charging side. The smoothing is performed and the charging control unit 104 supplies a DC voltage for charging to the battery 105.

  In the above embodiment, the same effects as those of the second embodiment can be obtained, and the portable terminal device 702 can be made smaller by sharing the rectifier diode for non-contact communication and power reception. .

  Next, the effect in the Example of this invention is demonstrated with reference to FIG.4, FIG.5 and FIG.6.

  FIG. 4 shows a conventional electromagnetic induction in which the transmitting side is composed of a magnetic resonance system and the receiving side is composed of a loop-shaped antenna coil and a resonant capacitor as shown in the second embodiment of the non-contact charging system of FIG. 25 shows the transmission efficiency characteristics when the system is used, and the experimental results of the transmission efficiency with respect to the distance between the coils when the conventional electromagnetic induction system is used on both the transmitting and receiving sides as shown in FIG. The distance between the coils, the vertical axis is the transmission efficiency.

  The diameter of the magnetic resonance coil on the transmission side in FIG. 2 is 4 cm, the number of turns is about 30 turns, the resonance frequency is about 20 MHz, and the reception side is based on a loop coil of about 3 turns with a diameter of 3 cm and a resonance capacity of 100 pF. This is a series resonance type loop antenna coil. The electromagnetic induction type transmission / reception coil shown in FIG. 25 has a diameter of 4 cm, a winding number of about 20 turns, a transmission frequency of about 120 kHz, and a resonance capacity of several μF.

  The conventional electromagnetic induction system shown in FIG. 25 is excellent in transmission efficiency when the distance between the coils is short, but the efficiency drops to about 50% when the distance between the coils is about 4 mm away. On the other hand, in the second embodiment, even when the distance between the coils is 4 mm, the efficiency is about 75%. Even when the distance between the coils is far away, transmission is performed by the magnetic resonance method, and reception is performed by the electromagnetic induction method. It can be seen that there is little decrease in transmission efficiency.

  FIG. 5 shows the frequency characteristics of transmission loss with respect to the distance between coils when the transmission and reception are both magnetic resonance systems as the non-contact power transmission system of the first embodiment shown in FIG. The experimental results of frequency characteristics of transmission loss in a conventional electromagnetic induction system composed of a loop coil of about 3 turns and a resonant capacitance are shown. The horizontal axis in the figure is the frequency and the vertical axis is the transmission loss. is there.

  Further, as the coil used in the experiment, the magnetic resonance method of FIG. 1 has a magnetic resonance coil diameter of 4 cm, a winding number of about 30 turns, a resonance frequency of about 20 MHz, and both the power supply coil and the load coil have a diameter. The number of turns is 3 cm and 1 turn. On the other hand, a conventional electromagnetic induction type loop antenna coil has a diameter of 4 cm, a winding number of about 3 turns, a transmission frequency of about 20 MHz, which is the same as the magnetic resonance system, and a resonance capacity of a few tens of pF.

  From the figure, it can be seen that the power transmission method using the magnetic resonance method of the first embodiment shown in FIG. 1 has frequency dependency depending on the distance between the coils, but has a smaller transmission loss than the conventional electromagnetic induction method.

  Next, FIG. 6 shows a second embodiment of the non-contact charging system shown in FIG. 2, in which the transmitting side is a magnetic resonance system as a non-contact communication means, and the receiving side is a loop of about 2 to 3 turns. The experimental result of the frequency characteristic with respect to the distance between coils when it is set as the electromagnetic induction system comprised with an antenna and a resonant capacity is shown. The coil used in the experiment has a diameter of 4 cm, the number of turns is about 3 turns, and the resonance capacity is a few hundreds of pF.

  Comparing FIG. 5 and FIG. 6, rather than using the magnetic resonance method for the transmission and reception shown in FIG. 5, the transmission side is the magnetic resonance method and the reception side is the conventional one as in the second embodiment shown in FIG. Since the magnetic field coupled loop antenna has less frequency characteristic fluctuation with respect to the distance between the coils, stable received power can be obtained regardless of the distance between the coils even when the transmission frequency is fixed at 13.56 MHz, for example. it can.

  FIG. 7a is a schematic diagram showing the configuration of the magnetic resonance type coil of the first embodiment of the non-contact charging system according to the present invention, and FIG. 7b shows FIG. FIG. 2 is a schematic diagram seen, and parts corresponding to those in FIG. The coil surfaces of the feeding coil 142, the magnetic resonance coils 141 and 101, and the load coil 102 are arranged in parallel to each other, and the distance between the coils on the z-axis is optimized with the configuration of FIG. Then, since the transmission efficiency between the coils is the highest, the following embodiment will be described based on the arrangement shown in FIG.

  FIG. 8 is a diagram showing a fourth embodiment of the non-contact charging (power transmission) system used in the present invention.

  In the figure, reference numeral 702 denotes a portable terminal device, 150 denotes a non-contact communication device, 420 denotes a power transmission device using an electromagnetic induction method, and the portable terminal device 702 in the figure includes an electromagnetic induction coil 401 that also serves as a magnetic resonance coil, and a load coil 402. , Resonance capacitor 403, low-pass filter 404, resonance capacitor 405, rectifier circuit 406, power supply circuit 407, load circuit 408, high-pass filter 409, load modulation circuit 410, detection / demodulation circuit 411, rectification circuit 412, memory 413, control circuit 414 It has. The electromagnetic induction power transmission device 420 includes an electromagnetic induction coil 421, a resonance capacitor 422, a power amplifier 423, an oscillator 424, a control unit 425, and a detection unit 426, and other parts corresponding to those in FIG. The description is omitted.

  In the figure, a mobile terminal device 702 has a resonance capacitor 403 connected in parallel with an electromagnetic induction coil 401 that also serves as a magnetic resonance coil, and a resonance capacitor 405 connected in parallel via a low-pass filter 404. A circuit 407 and a load circuit 408 are connected.

  Further, the load coil 402 is disposed close to the electromagnetic induction coil 401 that also serves as the magnetic resonance coil at a distance of several millimeters and is magnetically coupled to the electromagnetic induction coil 401 that also serves as the magnetic resonance coil. Further, the load coil 402 is connected to the load modulation circuit 410, the detection / demodulation circuit 411, and the rectification circuit 412 via the high-pass filter 409.

  In addition, a power transmission device 420 using an electromagnetic induction system has a configuration in which a resonance capacitor 422 is connected in parallel with the electromagnetic induction coil 421 and resonates with a power transmission signal frequency from the oscillation circuit 424 amplified by the power amplifier 423.

  In the above non-contact power transmission system, first, an operation in the case of performing non-contact communication from the non-contact communication device 150 to the portable terminal device 702 will be described.

  The oscillator 153 in the non-contact communication device 150 oscillates at a carrier frequency (for example, 13.56 MHz for RFID) in which non-contact communication is performed, and the non-contact data communication unit 154 and the modulation / demodulation circuit 430 transmit data to be transmitted. Correspondingly, the oscillation frequency is modulated, and the modulated communication signal is efficiently radiated as electromagnetic energy by the antenna adjusted so that the resonance frequency of the electromagnetic induction coil 151 and the resonance capacitor 152 is equal to the carrier frequency.

  On the other hand, in the portable terminal device 702, the resonance frequency in the electromagnetic induction coil 401 that also serves as the magnetic resonance coil and the resonance capacitor 403 is adjusted to be 13.56 MHz, which is the non-contact communication frequency, and thus also serves as the magnetic resonance coil. A large magnetic field flows through the electromagnetic induction coil 401 and a strong magnetic field is generated. Due to this strong magnetic field, the magnetically coupled load coil 402 is input to the detection and demodulation circuit 411 via the high-pass filter 409 and the load modulation circuit 410, and the received non-contact signal is demodulated and input to the control circuit 414. The control circuit 414 reads data corresponding to the received signal from the memory 413 and applies load modulation by the load modulation circuit 410. On the other hand, in the non-contact communication device 150, the modulation / demodulation circuit 430 detects and demodulates a change in the reception impedance of the mobile terminal device 702 in response to the load modulation from the load modulation circuit 410, and the non-contact data communication unit 154. It is the structure which transmits to. At this time, since the low-pass filter 404 blocks passage of the received signal frequency, the circuit after the low-pass filter 404 can be ignored, and the high-pass filter 409 has a pass characteristic with respect to the received signal frequency. The loss here can be neglected. In addition, power is supplied to the control circuit 414 and the memory 413 by using the power rectified by the rectifier circuit 412 from the signal received from the non-contact communication device 150, and a battery is unnecessary, and is built in the portable terminal device 702. The battery may be supplied from the battery.

  Next, an operation in a case where power is transmitted from the power transmission device 420 using the electromagnetic induction method to the portable terminal device 702 in a non-contact manner will be described.

  In the power transmission device 420 using the electromagnetic induction method, the detection unit 426 detects when the portable terminal device 702 is placed nearby, and the control unit 425 turns on the oscillator 424 and the power amplifier 423. As a result, the oscillator 424 oscillates at a frequency of, for example, a 100 kHz band lower than 13.56 MHz such as RFID used in the non-contact communication apparatus 150 as a frequency for transmitting power in a non-contact manner, and in the power amplifier 423. The power is amplified and the transmission power is supplied to the resonance circuit including the electromagnetic induction coil 421 and the resonance capacitor 422. Since the electromagnetic induction coil 421 and the resonance capacitor 422 resonate in the 100 kHz band that is the frequency of the supplied transmission power, a strong magnetic field flows in the electromagnetic induction coil 421 and a strong magnetic field is generated. At this time, since the portable terminal device 702 is placed close to the electromagnetic induction coil 421, the resonance circuit including the electromagnetic induction coil 401 that also serves as the magnetic resonance coil and the resonance capacitor 405 is equal to the frequency of the transmission power. Since the electromagnetic induction coil 401 that also serves as the magnetic resonance coil 421 is strongly coupled by electromagnetic induction, the power in the 100 kHz band received from the resonance capacitor 405 can be taken out. For this reason, the rectified circuit 406 connected to the resonant capacitor 405 rectifies the DC voltage and converts it to a constant voltage by the power supply circuit 407, and then the received power is supplied to the load circuit 408. At this time, since the low-pass filter 404 has a pass characteristic with respect to the frequency of the received power, the loss here can be ignored. In addition, since the high-pass filter 409 blocks passage of the received power frequency, the influence of the circuits after the load coil 402 and the high-pass filter 409 can be ignored.

  Further, a contactless charging system can be realized by replacing the power supply circuit 407 with a charge control circuit and the load circuit 408 with a battery.

  With the above configuration, non-contact power transmission by electromagnetic induction is performed on the received power in the 100 kHz band, and in non-contact communication at 13.56 MHz, the electromagnetic induction coil used for power reception is used as a magnetic resonance coil. In addition to the same effects as the non-contact charging (power transmission) system shown in FIG. 1, charging (power) that enables communication and power reception even when the frequency of non-contact communication differs from the frequency of non-contact power transmission. Transmission) system can be obtained.

  FIG. 9 is a diagram showing a fifth embodiment of the non-contact charging (power transmission) system used in the present invention.

  In the figure, 441 is a load modulation circuit, 442 is a detection and demodulation circuit, 443 is a control circuit, 444 is a modulation / demodulation unit, and other parts corresponding to those in FIG.

  In FIG. 9, a portable terminal device 702 has a configuration in which a load modulation circuit 441 and a detection / demodulation circuit 442 are added between a resonance capacitor 405 and a rectifier circuit 406. An electromagnetic induction power transmission device 420 includes an amplifier 423, A modulation / demodulation unit 444 is added between the resonance capacitors 422.

  In the figure, the non-contact communication between the non-contact communication device 150 and the portable terminal device 702 is the same as that of the fourth embodiment shown in FIG. An operation when power is transmitted to the device 702 in a non-contact manner will be described.

  In the power transmission device 420 using the electromagnetic induction method, a transmission power signal obtained by amplifying the oscillation signal from the oscillator 424 by the power amplifier 423 is modulated by the modulation / demodulation unit 444 and transmitted from the resonance coil 421. This transmitted power is received by the electromagnetic induction coil 401 that also serves as the magnetic resonance coil of the portable terminal device 702. The received power signal is rectified and received by the rectifier circuit 406, demodulated the signal received by the detection / demodulation circuit 442, and the received data signal is input to the control circuit 443. The control circuit 443 applies load modulation to the data signal corresponding to the received data signal by the load modulation circuit 441. This load modulation signal is demodulated by the modulation / demodulation unit 444 of the power transmission device 420 using the electromagnetic induction method.

  With the above configuration, the same effect as the non-contact charging (power transmission) system shown in FIG. 8 can be obtained, and also modulation can be applied to the transmission power signal in non-contact power transmission. This makes it possible to perform communication simultaneously with power transmission, for example, for the control required when performing authentication and transmission power control such as whether the mobile terminal device 702 supports non-contact power transmission. Communication can also be performed by superimposing power transmission and signals.

  FIG. 10 is a diagram showing a sixth embodiment of the contactless charging (power transmission) system used in the present invention.

  In the figure, 451 is a level detection circuit, 452 is a switching and power supply circuit, 453, 454 and 455 are field effect transistors, 456 is a rectifier circuit, and 460 is an electromagnetic induction type power transmission device. Further, the electromagnetic induction type power transmission device 460 includes an electromagnetic induction coil 461, a resonance capacitor 462, a power amplifier 463, an oscillator 464, a control unit 465, and a detection unit 467, and the other parts corresponding to FIG. A description will be omitted with reference numerals.

  In the figure, a portable terminal device 702 is provided with a level detection circuit 451 and a field effect transistor 453 between a resonance capacitor 403 and a resonance capacitor 405, and a rectifier circuit 406 is connected to a load circuit 408 via a switching and power supply circuit 452. Yes. Further, the load coil 402 is connected to a switching and power supply circuit 452 via a field effect transistor 454 and a rectifier circuit 456. Further, the electromagnetic induction type power transmission device 460 has a configuration in which a resonance capacitor 462 is connected in parallel with the electromagnetic induction coil 461 and resonates with the frequency of the transmission signal from the oscillation circuit 464 amplified by the power amplifier 463. The configuration is the same as that of the power transmission device 420 using the induction method, but the resonance frequency of the electromagnetic induction coil 461 and the resonance capacitor 462 and the oscillation frequency of the oscillator 464 are 13.56 MHz, which is equal to the resonance frequency of the non-contact communication device 150. .

  In the above non-contact power transmission system, first, a case where non-contact communication is performed from the non-contact communication device 150 to the mobile terminal device 702 will be described.

  The level detection circuit 451 of the portable terminal device 702 turns on the field effect transistor 455 and turns off the field effect transistors 453 and 454 in a state where no signal is received, thereby enabling the contactless communication device 150. When a non-contact communication signal of 13.56 MHz is received, the load modulation circuit 410, detection and demodulation are performed by magnetic resonance coupling including the electromagnetic induction coil 401 that also serves as the magnetic resonance coil, the resonance capacitor 403, and the load coil 402. The circuit 414 and the rectifier circuit 412 receive and communicate.

  Next, when the non-contact transmission power in the 100 kHz band is received from the electromagnetic induction power transmission device 420, the level detection circuit 451 turns on the field effect transistor 453 and turns off the field effect transistors 454 and 455. State. Accordingly, the resonance circuit constituted by the electromagnetic induction coil 401 that also serves as the magnetic resonance coil and the resonance capacitor 405 receives the transmission power from the power transmission device 420 by the electromagnetic induction method by the electromagnetic induction method, and switches the power supply to the rectifier circuit 406 and the power source. Electric power is supplied to the load circuit 408 through the circuit 452.

  Next, when receiving non-contact transmission power of 13.56 MHz from the electromagnetic induction power transmission device 460, the level detection circuit 451 turns on the field effect transistor 454 and turns off the field effect transistors 453 and 455. State. Thus, the magnetic resonance coupling constituted by the electromagnetic induction coil 401 that also serves as the magnetic resonance coil, the resonance capacitor 403, and the load coil 402 receives the transmission power from the power transmission device 460 by the electromagnetic induction method, and switches to the rectifier circuit 456. In addition, power is supplied to the load circuit 408 via the power supply circuit 452.

  With the above configuration, the same effect as the non-contact charging (power transmission) system shown in FIG. 8 can be obtained. In addition, with respect to non-contact power transmission, 100 kHz band power transmission is performed by electromagnetic induction. With regard to 13.56 MHz power transmission, power reception by magnetic resonance can be performed, so that power transmission by contact can be received even when the frequency band is different.

  FIG. 11 is a diagram showing a seventh embodiment of the non-contact charging (power transmission) system used in the present invention.

  In the figure, 470 is a non-contact communication unit, 471 is a charge control circuit, 472 is a battery, 473 is a high-pass filter, 480 is a non-contact communication device, and the non-contact communication unit 470 in the figure includes a switching circuit 474 and a modem circuit 475. The non-contact communication device 480 includes an electromagnetic induction coil 481, a resonance capacitor 482, a load modulation circuit 483, a detection / demodulation circuit 484, a rectifier circuit 485, and a control circuit. 486 and the memory 487, and other parts corresponding to those in FIG.

  In the figure, a portable terminal device 702 has a charge control circuit 471 and a battery 472 connected to the output of the rectifier circuit 406, and a load coil 402 to which a modulation / demodulation circuit 475 and an oscillator 476 are connected via a high-pass filter 473 and a switching circuit 474. . Further, a load modulation circuit 477 and a detection / demodulation circuit 478 are connected to the switching circuit 474.

  Further, the non-contact communication device 480 is connected to a resonance capacitor 482 in parallel with the electromagnetic induction coil 481, and is further connected to a load modulation circuit 483, a detection / demodulation circuit 484 and a rectifier circuit 485.

  In the figure, the operation in the case of receiving the transmitted power from the power transmission device 420 by the electromagnetic induction method will be described. A 100 kHz band transmission power signal transmitted from the power transmission device 420 is received by a resonance circuit including an electromagnetic induction coil 401 that also serves as a magnetic resonance coil of the mobile terminal device 702 and a resonance capacitor 405, and passes through a rectifier circuit 406 and a charge control circuit 471. The battery 472 is charged.

  Next, an operation in the case of performing non-contact communication from the non-contact communication device 150 to the mobile terminal device 702 will be described. The non-contact communication signal transmitted from the non-contact communication device 150 is received by a magnetic resonance method including an electromagnetic induction coil 401 that also serves as magnetic resonance, a resonance capacitor 403, and a load coil 402, and is switched via a high-pass filter 473. It is input to the circuit 474. Since the switching circuit 474 switches to the load modulation circuit 477 side when no signal is input, the received non-contact communication signal is modulated / demodulated by the detection / demodulation circuit 478 and the load modulation circuit 477. It becomes possible.

  Next, a case where communication with the non-contact communication device 480 is performed will be described. Since the non-contact communication device 480 does not have a built-in oscillator, for example, an RFID card or other passive communication that does not have a power source is used. Therefore, the mobile terminal device 702 wants to communicate with the non-contact communication device 480. Turns on the oscillator 476 and the modem circuit 475 and switches the switching circuit 474 to the modem circuit 475 side. As a result, the oscillation signal from the oscillator 475 is modulated by the modulation / demodulation circuit 475 and transmitted to the non-contact communication device 480. In the non-contact communication device 480, the received non-contact communication signal from the portable terminal device 702 is detected and demodulated by the demodulation circuit 484. Further, the non-contact communication signal from the non-contact communication device 480 is load-modulated by the load modulation circuit 483. The mobile terminal device 702 can communicate with the non-contact communication device 480 by demodulating the impedance variation from the modulation / demodulation circuit 475.

  With the above configuration, the same effect as the non-contact charging (power transmission) system shown in FIG. 8 can be obtained, and the non-contact communication device 150 can be an interrogator (reader / writer in RFID), non-contact communication. The device 480 corresponds to a responder (RFID card in RFID). Further, by adding a modulation / demodulation circuit 475 and an oscillator 476 (corresponding to an interrogator) in addition to a load modulation circuit 477, detection / demodulation circuit 478 (corresponding to a responder) to the mobile terminal device 702, an RFID without an internal oscillator is added. Communication with a card or the like becomes possible.

  FIG. 12 is a diagram showing an eighth embodiment of the non-contact charging (power transmission) system used in the present invention.

  In the figure, a portable terminal device 702 is a surface in which two portable terminal devices shown in the seventh embodiment of FIG. 11 are arranged close to each other, and the other portable terminal device has A dash (') is added to the figure number.

  In the figure, the operation when reading the contents of the memory 413 ′ in the mobile terminal device 702 ′ from the mobile terminal device 702 will be described. In the portable terminal device 702, the oscillator 476 and the modem circuit 475 are turned on, and the switching circuit 474 is switched to the modem circuit 475 side. As a result, the oscillation signal from the oscillator 475 is modulated by the modulation / demodulation circuit 475 and transmitted to the portable terminal device 702 '. Since the mobile terminal device 702 ′ normally switches to the load modulation circuit 477 ′, the received non-contact communication signal from the mobile terminal device 702 is detected and demodulated by the demodulation circuit 478 ′, and the control circuit 414 ′ receives the received data. Is read from the memory 413 ′ and the load modulation circuit 477 ′ performs load modulation. The portable terminal device 702 detects and demodulates the impedance variation by the modulation / demodulation circuit 475, and receives the received data signal from the portable terminal device 702 '.

  With the above configuration, the same effects as those of the non-contact charging (power transmission) system shown in FIG. 11 can be obtained, and a circuit (modem / demodulation circuit 475, oscillator 476) corresponding to an interrogator can be connected to the portable terminal device 702. ) Is added, non-contact communication is possible between portable terminal devices.

  FIG. 13 is a diagram showing a ninth embodiment of the non-contact charging (power transmission) system used in the present invention.

  In the figure, 501 is a power transmitter, 502 is a power receiver, 503 is a power supply coil, 504 is a primary resonance coil, 505 is a load circuit, 506 is a high-frequency power source, and the other corresponds to the fourth embodiment of FIG. The same reference numerals are assigned to the parts to be described, and the description is omitted.

  In the figure, a power transmitter 501 is composed of a high-frequency power source 506, a feeding coil 503, and a primary-side resonance coil 504. The primary-side resonance coil 504 is placed in the vicinity of the feeding coil 503, and the high-frequency power source is connected to the feeding coil 503. 506 is connected.

  The power receiver 502 includes a load coil 505, a rectifier circuit 406, a power supply circuit 407, and a load circuit 408. The load circuit 408 is connected to the load coil 505 via the rectifier circuit 406 and the power supply circuit 407. And the power receiver 502 constitute a non-contact power transmission system.

  In the figure, the power supply coil 503 is fed from a high frequency power source 506 at a frequency equal to the self resonance frequency determined by the stray capacitance (parasitic capacitance) between the self inductor of the primary side resonance coil 504 and the coil winding. The feeding coil 503 excites the primary side resonance coil 504 at a frequency equal to the self-resonance frequency by electromagnetic induction, whereby a large current flows through the primary side resonance coil 504 and a strong magnetic field is generated.

  Here, when the inductance value of the primary resonance coil is L and the stray capacitance between the lines is C, the self-resonance frequency f of the coil can be obtained by the following equation.

f = 1 / (2π√ (LC))
However, since the resonance frequency fluctuates depending on the coupling state of the feeding coil 503 and the load coil 505, the actual self-resonance frequency needs to be confirmed by simulation or experiment.

  With the above configuration, when the power receiver 502 is placed close to the power transmitter 501, a strong magnetic field from the primary resonance coil 504 is magnetically coupled to the load coil 505 of the power receiver 502, and both ends of the load coil 505 are connected. An electromotive force is generated between the children. The generated electromotive force is rectified to a DC voltage by the rectifier circuit 406 and input to the power supply circuit 407. In the power supply circuit 407, the voltage output from the rectifier circuit 406 varies depending on the transmission power and the distance between the primary resonance coil 504 and the load coil 505 due to a shift in the self-resonance frequency of the resonance coil and a change in transmission efficiency due to the distance between the coils. Therefore, it is converted into a constant voltage value required by the load circuit 408 and supplied to the load circuit 408.

  With the above-described configuration, the power transmitted from the power transmitter 501 can be received in a non-contact manner by magnetic coupling in the power receiver 502, and only the load coil 505 is used as a coil for the power receiver 502. Since power can be received, the receiver 502 can be downsized.

  Note that an example of the generally used size and number of turns of the coil shape shown in FIG. 13 shows that when charging a small portable device of about several W, the power supply coil 503 has a diameter of several centimeters and the number of turns. About 1 to several turns, the primary resonance coil 504 has a diameter of several centimeters, and the number of turns is about several tens of turns. The self-resonant frequency is 10 MHz, and the load coil 505 has a diameter of several centimeters. One turn or several turns.

  On the other hand, an example of a generally used size and number of turns of a coil shape used for power transmission of several tens of watts to several hundreds of watts, such as power supply and charging to a notebook personal computer, charging to an electric vehicle, etc. The feeding coil 503 has a diameter of several tens of centimeters, and the number of turns ranges from one turn to several turns. The primary side resonance coil 504 has a diameter of several tens of centimeters, the number of turns is several turns, and the self-resonant frequency ranges from several hundred Hz to 1 MHz. The load coil 505 has a diameter of several tens of centimeters, and the number of turns is about 1 to several turns.

  In the magnetic resonance method described above, if the loss due to the resistance component of the winding of the resonance coil is large, the transmission efficiency tends to decrease. Therefore, a copper wire having a diameter of about 1 mm to several mm is generally used as the coil wire. However, other wires may be used as long as the conductivity is high. The diameter of the coil for transmission and reception is related to the transmission distance, and the transmission distance tends to increase as the diameter increases. Moreover, higher efficiency is more easily obtained when the diameters of the transmission and reception coils are equal to each other. However, since the coupling between the coils is stronger than that of the conventional electromagnetic induction method, relatively high transmission efficiency is obtained even if the diameters of the transmission and reception coils are slightly different. Obtaining it is also a feature of the magnetic resonance method.

  From this, the diameter of each coil may be the same or different, and each coil may be a cylindrical coil or a spiral planar coil. Furthermore, the planar coil may be formed as a copper pattern on the substrate, or may be formed on a film.

  Next, a tenth embodiment of the non-contact charging (power transmission) system of the present invention will be described with reference to the drawings.

  FIG. 14 is a diagram showing a tenth embodiment of the non-contact power transmission system used in the present invention.

  In the figure, reference numeral 511 denotes a load coil having resonance, 512 denotes a resonance capacitor, and other parts corresponding to those in FIG.

  14, compared with the ninth embodiment of the non-contact charging system shown in FIG. 13, a load coil 511 having resonance and a resonance capacitor 512 are connected in series to form a series resonance circuit. The values of the load coil 511 having resonance and the resonance capacitance 512 are determined so that the resonance frequency becomes equal to the self-resonance frequency of the primary resonance coil 504. In addition, the inductance value of the load coil 511 having resonance is larger than the inductance value of the feeding coil 503.

  With the above configuration, the same effect as that of the ninth embodiment shown in FIG. 13 can be obtained, and in addition, a resonance circuit is configured by the load coil 511 and the resonance capacitor 512 having resonance. Since it is strongly coupled with the magnetic flux from the primary resonance coil 504, a decrease in transmission efficiency when the distance between the coils is increased can be further reduced. In other words, even if the distance between the coils varies, the change in the input impedance is reduced, so that the variation in the frequency characteristics due to the distance between the coils can be reduced.

  For example, when the coil diameter is several centimeters, the transmission distance is about several centimeters, and when the diameter is several tens of centimeters, a transmission distance of about several tens of centimeters to 1 meter is obtained. A long transmission distance can be obtained.

  FIG. 15 is a diagram showing an eleventh embodiment having a non-contact power transmission system used in the present invention.

  In the figure, 521 is a primary resonance coil, 522 is a resonance capacitor, 523 is an excitation coil, and the other parts corresponding to those in FIG.

  In the figure, when a signal equal to the resonance frequency determined by the inductance value of the primary side resonance coil 521 and the capacitance value of the resonance capacitor 522 is supplied from the high frequency power source 506 via the excitation coil 523, the resonance phenomenon is caused by the resonance coil 521 and the resonance capacitor 522. A large current flows and a strong magnetic field is generated. In this configuration, it is mainly used for high power transmission of several tens of watts or more. When a general example of the size and the number of turns of the coil is shown, the diameter of the resonance coil 521 is about several tens of cm to 1 m, and the wire diameter of the coil is About 1 cm, the number of turns is about 1 to 2 turns. The excitation coil has a wire diameter of about several millimeters, and a general method is to wrap around the resonance coil 521 or excite using a magnetic material such as a ferrite core.

  FIG. 15 shows that the resonance coil on the primary side is locally electromagnetically induced by using the excitation coil 523 instead of the feeding coil, as compared with the tenth embodiment of the non-contact power transmission system shown in FIG. In addition to obtaining the same effect as that of the tenth embodiment, the power transmission side resonance coil can be configured with about one turn, so that the power transmission side can be downsized.

  FIG. 16a is a diagram showing a twelfth embodiment having a non-contact charging (power transmission) system used in the present invention.

  In the figure, reference numeral 531 denotes a primary resonance coil group, which is composed of spiral-shaped resonance coils 531a and 531b, which are wound in a spiral at a constant interval in parallel. Here, the spiral-shaped resonance coils 531a and 531b are configured to have different self-resonance frequencies. In addition, portions corresponding to those in FIG.

  In FIG. 16a, the number of turns of the spiral resonance coils 531a and 531b is adjusted so as to be most efficient at different distances within a distance that can be received by the power receiver 502. For example, when the distance a is the distance at which the spiral resonance coil 531a is most efficient and the distance b is the distance at which the resonance coil 531b is most efficient, the distance between the resonance coil 531 on the primary side and the load coil 511 having resonance. Is a distance a, the power supplied from the power supply coil 503 is mainly supplied to the load coil 511 having resonance via the spiral resonance coil 531a, while the spiral resonance coil 531b is optimal in impedance matching. Since it deviates from the value, power is hardly transmitted. When the distance between the resonance coil 531 on the primary side and the load coil 511 having resonance is the distance b, the power supplied from the power supply coil 503 is a load having resonance mainly via the spiral resonance coil 531b. It is supplied to the coil 511.

  Note that the self-resonant frequency can be changed by changing the coil winding length (number of turns) of the spiral-shaped resonance coils 531a and 531b and the coil diameter of the coil winding.

  At this time, since the parasitic capacitance between the coils is wound in parallel with each other, the self-resonant frequency must be obtained by simulation or experiment because there is an influence of the mutual coupling in addition to the influence of the feeding coil and the load coil. is necessary.

  With the above configuration, the same effect as that of the tenth embodiment shown in FIG. 14 can be obtained, and on the power transmitter side, the primary side resonance coil 531 and the load coil 511 having resonance can be obtained. The variation in frequency characteristics due to the distance between the coils can be further reduced.

  FIG. 16 b shows another example of the primary resonance coil group 531.

  In the figure, reference numeral 532 denotes a cylindrical resonance coil group, which is composed of cylindrical resonance coils 532a and 532b, which are wound in parallel in a cylindrical shape at regular intervals, and have different self-resonant frequencies. . The self-resonant frequencies can be changed by changing the coil winding length (number of turns) of the cylindrical resonance coils 532a and 532b, the coil winding wire diameter, and the coil inner diameter.

  In these figures, the coil group has two configurations in the figure, but may be three or more. If power can be supplied by the power supply coil, the coils may be independent of each other without being wound in parallel. A spiral planar coil and the other cylindrical coil may be used.

  FIG. 22 shows the frequency characteristics between the transmitting and receiving coils in the case where the plurality of resonance coils are used. In the figure, the transmission characteristic between the primary side feeding coil and the secondary side load coil in the case where the primary side resonance coil shown in FIG. 16a is composed of a plurality of coils having different self-resonance frequencies is schematically shown. It is a schematic diagram. In the figure, the horizontal axis represents frequency and the vertical axis represents transmission loss. In the figure, it can be seen that the use of coils having different self-resonance frequencies for the resonance coil broadens the frequency characteristics. Thereby, even when the frequency characteristic fluctuates due to the distance between the coils, it is possible to reduce the decrease in transmission efficiency due to the widened frequency band.

  FIG. 17 is a diagram showing a thirteenth embodiment of a non-contact charging (power transmission) system used in the present invention.

  In the figure, 542 is a level detection circuit, 543 is a control circuit, 541 is a field effect transistor, and other parts corresponding to the tenth embodiment of the non-contact power transmission system shown in FIG. The description is omitted.

  Compared with the tenth embodiment shown in FIG. 14, the drain and the source of the field effect transistor 541 are connected to both ends of the resonance capacitor 512. Further, a part of the DC output rectified by the rectifier circuit 406 is detected by the level detection 542 and output to the control circuit 543. The control circuit 543 uses a part of the power supply voltage rectified by the power supply circuit 407 as a power source. Thus, the gate of the field effect transistor 541 is controlled.

  In the above configuration, when the field effect transistor 541 is in the OFF state, the magnetic field generated by the primary side resonance coil 504 is strongly coupled to the resonance circuit composed of the load coil 511 having resonance and the resonance capacitor 512, A reception current flows through the rectifier circuit 406 through these resonant circuits. At this time, when the control circuit 543 turns on the field effect transistor 541, both ends of the resonance capacitor 512 are short-circuited, so that the load coil 511 having resonance has no resonance point. For this reason, the magnetic field generated by the primary resonance coil 504 supplies received power to the rectifier circuit 406 by electromagnetic induction that does not cause resonance on the secondary side by the load coil 511. The control circuit 543 compares the rectified voltage output from the rectifier circuit 406 by periodically turning on and off the field effect transistor 541, and performs an operation of switching to a higher received power.

  The power reception in the resonance state by the load coil 511 and the resonance capacitor 512 has the highest transmission efficiency when the distance between the primary side resonance coil 504 and the load coil 511 is some distance, and conversely, the distance between the coils is several mm or less. At very close distances, transmission efficiency decreases due to impedance fluctuations. On the other hand, when power is received by only the load coil 511, the power receiving side does not have a resonance circuit, and electromagnetic induction transmission is performed at a very short distance. Therefore, if the power receiving side does not have a resonance circuit, the transmission efficiency is higher. This is because the coupling between the feeding coil and the resonance coil and the coupling between the resonance coil and the load coil can be regarded as transmission by the same electromagnetic induction. For this reason, when the distance between the coils is some distance away, the field effect transistor 541 is turned off, and at a very short distance, the field effect transistor 541 is turned on so that the power receiving side does not have a resonance circuit. In addition to the effects similar to those of the tenth embodiment shown in FIG. 14, it is possible to obtain a non-contact power transmission system in which the degradation of transmission efficiency is small even when the distance between the coils is very short.

  FIG. 23 is a schematic diagram schematically showing the effect of turning on and off the resonance capacitor connected in series with the load coil by the field effect transistor. In the figure, the horizontal axis represents the distance between the coils, and the vertical axis represents the transmission loss. In the figure, when the field effect transistor is turned on, the load coil does not have a resonance frequency and transmission is performed by electromagnetic induction. Therefore, the loss increases rapidly as the distance between the coils increases. On the other hand, when the field effect transistor is turned off, the load coil becomes a series resonance circuit due to the resonance capacitance, so the increase in transmission loss is small even if the distance between the coils is some distance away, but the transmission efficiency is rather low when the distance is very short. descend. Therefore, it can be seen that if the field effect transistor is turned on at a very short distance so that the load coil does not have a resonance circuit, a decrease in transmission efficiency at a short distance can be suppressed.

  FIG. 18 is a diagram showing a fourteenth embodiment having a non-contact charging (power transmission) system used in the present invention.

  In the figure, 551a, 551b, and 551c are field effect transistors, 552a, 552b, and 552c are resonance capacitors, 553 is a resonance capacitor, and parts corresponding to the thirteenth embodiment shown in FIG. Description is omitted.

  In the figure, compared to the thirteenth embodiment shown in FIG. 17, a resonance capacitor 553 is connected in parallel with the primary side resonance coil, and the load coil 511 having resonance has field effect transistors 551a, 551b, 551c and resonance capacitors 552a, 552b, and 552c connected in series are connected in parallel.

  Electric power is supplied from the feeding coil 503 at a self-resonant frequency determined mainly by the inductance value of the primary side resonance coil 504 and the resonance capacitance 553. Since the primary side resonance coil 504 is fed at a self-resonance frequency with the resonance capacitor 553, a large current flows through these resonance circuits and a strong magnetic field is generated. At this time, since the resonance capacitor 553 is connected in parallel with the primary resonance coil 504, when compared at the same resonance frequency, the inductance value of the primary resonance coil 504 is made smaller than when there is no resonance capacitance. Therefore, the shape of the power transmitter 501 can be reduced.

  On the other hand, the resonance capacitors 552a, 552b, and 552c connected in series with the field effect transistors 551a, 551b, and 551c constitute a parallel resonance circuit with the load coil 511 having resonance, and each capacitor has a resonance frequency. The capacitance values are different. For this reason, it is the structure which selects the capacity | capacitance value from which the transmission efficiency becomes the highest with the distance between coils of the primary side resonance coil 504 and the load coil 511 which has resonance.

  An example of means for selecting an optimum capacitance value in the above configuration will be described below.

  When the magnetic field from the primary side resonance coil 504 is received by the load coil 511 having resonance, the control circuit 543 turns on the field effect transistor corresponding to the resonance capacity that increases the transmission efficiency when the distance between the coils is the longest. Keep it. When power reception starts, the control circuit 543 periodically turns on other field effect transistors that are in the off state, and detects the received power at that time by the level detection 542. And by selecting the resonance capacity with the largest received power, it is possible to receive power with high transmission efficiency. At this time, the control circuit 543 periodically detects the received power from the level detection 542, selects the field effect transistor with the highest transmission efficiency, and turns it on.

  With the above configuration, the same effects as those of the thirteenth embodiment shown in FIG. 17 can be obtained, and a plurality of resonance capacitors are provided and switched using field effect transistors, thereby further improving the power transmission efficiency depending on the distance between the coils. Optimization is possible.

  When the distance between the coils is short (in the case of a coil having a diameter of several centimeters, about 1 cm or less), there is a parasitic capacitance between the coil winding of the resonance coil 504 and the coil winding of the load coil 511. When the distance is short, the self-resonant frequency of the resonance coil is lowered by increasing the capacitance between the resonance coil and the load coil. In this case, when the power transmission frequency is constant, the resonance capacity of the load coil is reduced as the distance gets shorter, and the resonance frequency due to the load coil and the resonance capacity is increased, thereby suppressing the decrease in the self-resonance frequency of the resonance coil. Therefore, fluctuations in transmission efficiency due to the distance between the coils can be suppressed.

  FIG. 19 is a diagram showing a fifteenth embodiment having a non-contact charging (power transmission) system used in the present invention.

  In the figure, the power transmission device 610 includes a power supply coil 611, a spiral-shaped primary resonance coil 612, a modulation / demodulation circuit 613, a variable gain power amplifier 614, an oscillator 615, and a control circuit 616. In addition, non-contact power in FIG. Portions corresponding to the thirteenth embodiment of the transmission system are denoted by the same reference numerals and description thereof is omitted.

  The spiral-shaped primary resonance coil 612 shown in the figure is a coil wound on a plane, and has a self-resonance frequency due to a parasitic capacitance between coil windings as in the case of a cylindrical solid coil, and the resonance frequency is a cylindrical coil. It is calculated in the same way as

  In addition, a load modulation circuit 441 and a detection / demodulation circuit 442 are added between the resonant load coil 511 and the rectifier circuit 406 in the mobile terminal device 702, and the power transmission device 610 supplies variable gain power to the high frequency power source 615. The amplifier 614 and the modulation / demodulation circuit 613 are connected to the feeding coil 611.

  In the above configuration, power is transmitted from the power transmission device 610 to the portable terminal device 702 in a contactless manner, and authentication and transmission power control between the power transmission device 610 and the portable terminal device 702 necessary for power transmission are performed. It has the necessary communication means.

  First, an operation of transmitting power from the power transmission device 610 to the mobile terminal device 702 in a contactless manner will be described.

  A signal output from the high frequency power source 615 at a frequency equal to the self-resonant frequency of the primary side resonance coil 612 is amplified by the variable gain power amplifier 614 and fed to the feeding coil 611 via the modulation / demodulation circuit 613. Since the fed power transmission signal has a frequency equal to the self-resonance frequency of the primary resonance coil 612, a strong magnetic field is generated from the primary resonance coil 612.

  On the other hand, the power supply coil 511 having resonance is strongly coupled to the magnetic field from the primary resonance coil 612 due to resonance with the resonance capacitor 512, so that power is efficiently received, and the load modulation circuit 441, detection and demodulation circuit 442 are received. Is supplied to the load circuit 408 via the power supply circuit 407. In addition, the control circuit 543 performs an operation of turning the field effect transistor 541 on or off with reference to the value of the level detection 542 and switching the received power to the larger one.

  Next, the operation in the case of performing contactless communication will be described first in the case where data is transmitted from the power transmission device 610 to the mobile terminal device 702.

  In the figure, the power transmission signal from the variable gain power amplifier 614 is subjected to modulation such as ASK modulation to be fed to the feeding coil 611. The fed power transmission signal generates a stronger magnetic field than the primary resonance coil 612, is efficiently received by the load coil 511 having resonance, and the resonance capacitor 512, and is input to the detection / demodulation circuit 442 via the load modulation circuit 441. Is done. The input power transmission signal is demodulated by a detection circuit using a diode or the like and input to the control circuit 502. The received power is rectified by the rectifier circuit 406 and supplied to the load circuit 408 by the power supply circuit 407.

  Next, a case where data is transmitted from the mobile terminal device 702 to the power receiving device 610 will be described.

  When performing communication, since the mobile terminal device 702 receives power from the power transmission device 610, the signal amplitude is always applied to the load modulation circuit 441 as well. For this reason, in the load modulation circuit 441, when the impedance at this point is changed in accordance with the modulation signal, the impedance on the side of the power transmission device 610 that is magnetically coupled is also affected and changes (load modulation method). Therefore, the modulation / demodulation circuit 613 can extract the signal demodulated by reflection of the transmission power generated by the load fluctuation of the load modulation circuit 441 by diode detection or the like, so that communication is possible.

  With the above configuration, it is possible to obtain a non-contact power transmission system having communication means capable of communicating with a simple configuration while obtaining the same effect as the thirteenth embodiment of the non-contact power transmission system of FIG. Can do.

  FIG. 20 is a diagram showing a sixteenth embodiment having a non-contact charging (power transmission) system used in the present invention.

  In the figure, 631 is a primary side resonance coil group, 632 is a power supply coil, and the primary side resonance coil group 631 is constituted by spiral-shaped resonance coils 631a and 631b, which are arranged in parallel at regular intervals. The other parts corresponding to the fourteenth embodiment of the non-contact power transmission system of FIG. 18 and the fifteenth embodiment of the non-contact power transmission system of FIG. 19 are denoted by the same reference numerals. Description is omitted.

  In the figure, a spiral resonance coil 631a and a plurality of coils 631b are used as the primary resonance coil of the power transmission device 610, and the number of turns of the coil is changed so that the self-resonance frequency is different. Further, the positional configurations of the primary side resonance coil group 631 and the power supply coil 632 are changed, and the load having resonance with the power supply coil 632 rather than the distance between the load coil 511 having resonance with the primary side resonance coil group 631. The distance between the coils 511 was made closer.

  With the above configuration, the twelfth embodiment of the non-contact power transmission system of FIG. 16a, the fourteenth embodiment of the non-contact power transmission system of FIG. 18 and the fifteenth embodiment of the non-contact power transmission system of FIG. In addition to the same effects as the embodiment, the distance between the feeding coil 632 and the load coil 511 having resonance is closer than the distance between the primary side resonance coil group 631 and the load coil 511 having resonance. By doing so, when the inter-coil distance between the power supply coil 632 and the load coil 511 having resonance is very short, the power supply coil 632 has resonance rather than magnetic resonance transmission via the primary resonance coil group 631. Since it is possible to transmit directly to the load coil 511 by electromagnetic induction, it is possible to suppress a decrease in transmission efficiency at a very short distance.

  With the above configuration, when the inter-coil distance is reduced, the resonance frequency of the resonance coil is increased due to the proximity of the load coil, so that the resonance frequency is lowered. Therefore, the transmission efficiency is lowered when the transmission frequency is constant. In this case, by changing the arrangement of the resonance coil and the power supply coil, the distance between the power supply coil and the load coil is reduced, and the resonance coil does not enter between them, so that coupling between the power supply coil and the load coil is enhanced by electromagnetic induction. . At this time, when the distance between the coils is long, the transmission by electromagnetic induction is small, but when the distance between the coils is very short, the resonance frequency of the resonance coil shifts to the lower side, but the transmission by electromagnetic induction between the feeding coil and the load coil is not. Since it becomes large, a decrease in transmission efficiency when the distance between the coils is very short can be suppressed.

  FIG. 21 is a diagram showing a seventeenth embodiment having a non-contact charging (power transmission) system used in the present invention.

  In the figure, 641 and 651 are antennas, 642 is a load modulation circuit, 643 is a detection and demodulation circuit, 652 is a modulation / demodulation circuit, and 653 is an oscillation circuit, which corresponds to the fifteenth embodiment of the non-contact power transmission system of FIG. The same reference numerals are assigned to the parts to be described, and the description is omitted.

  An oscillation circuit 653 is connected to an antenna 651 through a modulation / demodulation circuit 652 in the power transmission device 610 in the figure, and an antenna 641 is connected to the detection / demodulation circuit 643 through the load modulation circuit 642 in the portable terminal device 702.

  An operation of performing communication between the power transmission device 610 and the mobile terminal device 702 in the above configuration will be described. Note that description of the power transmission operation is omitted.

  In the figure, the modulation / demodulation circuit 652 modulates the transmission signal from the oscillation circuit 653 and feeds it to the antenna 651. The supplied transmission signal is radiated as electromagnetic energy or magnetic energy by the antenna 651. The radiated transmission signal is received by the antenna 641 and input to the detection / demodulation circuit 643 via the load modulation circuit 642. The input transmission signal is demodulated by a detection circuit such as diode detection and input to the control circuit 604.

  Next, a case where data is transmitted from the mobile terminal device 702 to the power transmission device 610 will be described. Considering the case where the mobile terminal device 702 performs communication when the power transmission device 610 is receiving a signal, the signal amplitude is always added to the load modulation circuit 642 as well. For this reason, the load modulation circuit 642 is configured to use a load modulation system that performs modulation by changing the load at this point.

With the above configuration, the same effect as that of the fifteenth embodiment of the non-contact power transmission system of FIG. 19 can be obtained, and communication can be performed at a frequency different from that of power transmission, so that communication can be performed at higher speed. Therefore, other data can be transmitted in addition to control data necessary for power transmission such as authentication and transmission power control.

101, 141, 504, 521, 612 ... magnetic resonance coil, 102, 402, 505 ... load coil, 103, 154, 221, 312 ... non-contact data communication unit, 104 ... charge control unit, 105, 472 ... battery, 106: terminal wireless communication unit, 107: detection output unit, 101, 210 ... changeover switch, 111, 112, 211 ... attenuation resistor, 121, 122, 123, 124, 125, 126, 127, 128 ... rectifying diode, 130 131, smoothing capacitors, 140, 220, 310, 420, 460, 610, 701 ... power transmission device, 142 ... feeding coil, 143 ... amplifying unit, 144, 153, 424, 464, 476, 615 ... oscillator, 145, 425, 465 ... control unit, 146 ... detection unit, 151, 401, 421, 461, 481 ... electromagnetic induction Coil, 152, 301, 302, 405, 422, 462, 482, 512, 552a, 552b, 552c, ... resonance capacity, 311 ... combiner, 313 ... filter, 711 ... power transmission control module, 712 ... non-contact power transmission module , 713 ... Non-contact processing module, 720 ... Large-capacity storage module, 721 ... Power reception control module, 722 ... Non-contact power reception module for charging, 723 ... Non-contact processing module, 150, 460, 480 ... Non-contact Communication device 403, 553, 738, 739 ... resonance capacitance, 404 ... low pass filter, 406, 412, 456, 485 ... rectifier circuit, 407 ... power supply circuit, 408 ... load circuit, 409, 473 ... high pass filter, 410, 441 477, 483, 642 ... load modulation circuit, 411, 442, 78 ... Detection and demodulation circuit, 413, 487, ... Memory, 414, 443, 486, 543, 616 ... Control circuit, 430, 475, 613, 652 ... Modulation / demodulation circuit, 153 ... Oscillator, 453, 454, 455, 541, 521a, 521b, 521c, 551a, 551b, 551c ... field effect transistor, 452 ... switching and power supply circuit, 471 ... charge control circuit, 501 ... power transmitter, 502 ... power receiver, 505, 511 ... load coil, 506 ... high frequency power source 523: Excitation coil, 531, 532, 631 ... Resonance coil group, 542 ... Level detection circuit, 614 ... Variable gain power amplifier, 641, 651 ... Antenna

Claims (2)

A primary side coil including a power supply coil and a magnetic resonance coil and a secondary side coil including a load coil are provided. Electric power is supplied from the power supply coil at a resonance frequency of the magnetic resonance coil, and is supplied from the primary coil. A non-contact power transmission system for non-contact transmitting power to the load coil of the secondary coil,
The coupling between the feeding coil and the magnetic resonance coil, and the coupling between the magnetic resonance coil and the load coil transmit power in a non-contact manner using magnetic coupling,
Connecting a resonance capacitor in parallel with the magnetic resonance coil, supplying power at a resonance frequency determined by the inductance of the magnetic resonance coil and the resonance capacitance,
A resonance circuit is formed by connecting a resonance capacitor that resonates with the inductance of the load coil by serial connection or parallel connection to the load coil of the secondary coil,
The primary resonance circuit by the magnetic resonance coil and the resonance capacitor and the secondary resonance circuit by the load coil and the resonance capacitor are configured to have the same resonance frequency,
By making the number of turns of the load coil smaller than the number of turns of the magnetic resonance coil, the inductance value of the load coil is made smaller than the inductance value of the magnetic resonance coil, and the number of turns of the load coil is set to the power supply. More than the number of turns of the coil, the inductance value of the load coil is larger than the inductance value of the feeding coil,
The load coil is connected to a rectifier circuit, and supplies power transmitted from the primary coil to the rectifier circuit. The contactless power transmission system according to claim 1,
When a resonant capacitor that resonates with the load coil of the secondary coil is connected in series, a switching element is added in parallel with the resonant capacitor, and the resonant capacitor that resonates with the load coil of the secondary coil When connected in parallel, a switch element is added in series with the resonant capacitor,
A contactless power transmission system, wherein received power is compared between when the switch element is turned on and when the switch element is turned off, and the switch element is switched to the one with higher received power to transmit power.

Images